Field of the Invention
The present invention relates to an image processing technique for generating an image corresponding to a predetermined three-dimensional shape by transforming an image captured by an image-capturing device.
Description of the Related Art
Conventionally, there has been known a technique for generating an overhead image illustrating a state where an object is seen from a higher and virtual viewpoint that is different from a position of an image-capturing device by transforming an image of a periphery of the object captured by the image-capturing device.
Japanese Patent Application Laid-Open No. 2013-137698 discusses a technique for generating an overhead image illustrating a state where a vehicle is seen from a higher and virtual viewpoint set to a point above the vehicle by transforming an image captured by an in-vehicle image-capturing device that captures an image of the lower portion of the vehicle.
According to the technique discussed in Japanese Patent Application Laid-Open No. 2013-137698, a virtual projection plane having a three-dimensional shape is set, and pixels of an image actually captured by the in-vehicle image-capturing device are projected onto the virtual projection plane, thereby generating an overhead image.
However, in the technique discussed in Japanese Patent Application Laid-Open No. 2013-137698, the image is transformed without distinguishing whether the object captured by the in-vehicle image-capturing device is a road surface or a wall. In other words, in the technique discussed in Japanese Patent Application Laid-Open No. 2013-137698, the image is transformed based on an assumption that all of the objects captured by the in-vehicle image-capturing device are road surfaces. Accordingly, in a case where an image captured by the in-vehicle image-capturing device includes an image of a wall, an image of a road surface is displayed with less deformation when the image is transformed into an overhead image. However, because the same image processing as that executed on the image of the road surface is executed on the image of the wall, the shape of the image of the wall may be deformed after transformation.
According to the present invention, an object in a captured image is expressed in a desired shape in a case where an image corresponding to a three-dimensional shape is generated by transforming an image captured by an image-capturing device.